In manufacturing complimentary Organic Thin Film Transistors (OTFTs) treatment of source and drain printed silver (Ag) electrodes for the p-type or n-type OTFT is at times undertaken in order to modify the work function of the source and drain electrodes. Such electrode modification is typically conducted using non-selective processing techniques which include an immersion of the substrate in a modifier solution. This then requires additional steps including at least those of material removal and/or cleaning such as of the solvent. It is therefore considered useful to provide methods and systems employing more selective processing techniques, which in turn streamlines and simplifies the overall manufacturing of OTFTs.